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#1

News & Events / Re: Release of Amstrad Cpc Crt...

Last post by SerErris - Today at 22:58

@SerErris :
I think I have accurately specified the number of the T cycle in an M cycle but I did not go into detail about the M cycles of the Z80A (I use the same references)
I also explain that the Opcode Fetch is done during M1 a little before when I describe the opcode fetch.
The cycle indicated TW in the IO REQ is the 3rd of cycle T of cycle M, even if T3 in the nomenclature is the 4th.
Even if the objective of the document is not to further describe the internal workings of the Z80A, I thank you for the precision and I have clarified the cycle number M

It is now much clearer in the english version. Thanks for the add.
However in Section 4.4.4 there is now this in the wording:

A cycle M consists of several T cycles, one of which has the particularity of taking into account the signal sent to the Wait pin by an external component. This wait cycle is commonly named Tw. At this Tw cycle it honors an active High signal and runs Wait cycles until this line getting down again.

It is actually a active low signal. /WAIT and it is working exactly the opposite way. So if it is low, the CPU will run wait cycles and if it is getting high again, the CPU will continue.
It is a little bit confusing as the Signal from the GA is called READY (active High). But that is aligned as READY is the opposite of /WAIT. So the Gatearray pulls the line high (actually a pull up does that) and the CPU can run. It pulls it low and the CPU will wait. The GA actually keeps this line low for 66% of the M cycle and only 33% it is high. That will lead to the synchronization we all know about.
So the sentence should read:

A cycle M consists of several T cycles, one of which has the particularity of taking into account the signal sent to the /WAIT pin by an external component. This wait cycle is commonly named Tw. At this Tw cycle it honors an active low signal on /WAIT and runs wait cycles until this line getting up again.

#2

News & Events / Re: Release of Amstrad Cpc Crt...

Last post by SerErris - Today at 22:47

What is this project you are currently working on regarding Vortex?

I do need to reverse envineer the ROM that is actually scrambled utilizing the M1 line. So depending on the M1 cycle it does scramble (actually descramble) or does not descramble the ROM. So if you read the ROM just normally (dump it, or read it with CPC) you will get all databytes scrambled and it is unusable. 

I like to preserve it and get the unscrambled version (and commented source code). 

So the way I now try to fill the remaining holes is, to sniff all rom reads with a Raspberry Pi PICO. 

I have worked the last weekend on the code, which now looks ready (it does what I want it to do), and I can now hook up a CPC to this thing and start sniffing.

If you are interested in more detail, I could explain it, but probably not in this thread :-)

#3

General Discussion - Introductions / Re: Memorable CPC game intros ...

Last post by ZorrO - Today at 22:29

Black Land (1998)
Fres Fighter II Turbo (1999)

In those times most people already had 32bit, so could miss this titles.

#4

Applications (CPC and CPC-related) / Re: CubeMDOS / FAT16+FAT32-OS ...

Last post by HAL6128 - Today at 22:28

Here are two more possibilities / alternativs. Maybe it helps? Look at the thread from @Ast 
A piece of assembler code by him or the use his ImpDos ?
https://www.cpcwiki.eu/forum/programming/rom-initialisation/

#5

G

Applications (CPC and CPC-related) / Re: CubeMDOS / FAT16+FAT32-OS ...

Last post by Galatronic - Today at 21:01

Hm, maybe I was a little too fast with my assumption. I thought that the MegaFlash could also replace the Lower ROM, but it seems that it doesn't. So, the Firmware ROM ( X-MEM - CPCWiki ) won't be usable (which initialize ROMs 0-31).
How about using UniDOS as an IDE interface driver? Which interface do you use?

I prefer cubemdos because most easy to use... I'm using a cpc6128 and  a megaflash that could be able to replace the rom 0 (but not the dos rom 7) . But seems that cubemdos and 32rombooster rom can't live togheter ...

#6

Amstrad CPC hardware / Re: I found it. My DIY hardwar...

Last post by McArti0 - Today at 20:37

McArti0 interface Amiga mouse for CPC by Joy from 1992 - full PINout

#7

General Discussion - Introductions / Re: Memorable CPC game intros ...

Last post by HAL6128 - Today at 20:29

And I remember the games from Bollaware:

- Back Land
- FresFighter

Wow both are great!!

Yeah, Bollaware is great!

#8

Applications (CPC and CPC-related) / Re: CubeMDOS / FAT16+FAT32-OS ...

Last post by HAL6128 - Today at 20:28

Hm, maybe I was a little too fast with my assumption. I thought that the MegaFlash could also replace the Lower ROM, but it seems that it doesn't. So, the Firmware ROM ( X-MEM - CPCWiki ) won't be usable (which initialize ROMs 0-31).
How about using UniDOS as an IDE interface driver? Which interface do you use?

#9

G

Applications (CPC and CPC-related) / Re: CubeMDOS / FAT16+FAT32-OS ...

Last post by Galatronic - Today at 20:06

Don't know about the Problem, but instead of using the old Booster Rom you could try the more modern Firmware Rom 3.15 / 3.16?

Can you tell me more please?

#10

General Discussion - Introductions / Re: Memorable CPC game intros ...

Last post by ZorrO - Today at 19:44

North & South
Back to the Future 2
Switchblade